Tension device for moving-picture machines.



N. POWER. maswn DEVICE FOR movme Emma MACHINES.

APPLICATION FILED JUNE 6, I916- Patented July 2,1918.

anueufoz -it may be quickly removed and rep I sition for projection at the UNIT D sTATEs PATENT orries." l

NIGHOLAJS POWER, or BROOKLYN, NEW Y ORK, ASSIGNOR T0 NICHOLAS POWER COM- PANY, OF NEW YOBK,,N. Y., A. CORPORATION OF DELAWARE.

To all whom it mag concern:

Be it known that ii, NICHOLAS POWER, a citizen of the United States, and a resident of the borough of Brooklyn, city and State of New York, have invented new and useful Improvements in Tension Devices for Moving-Picture Machines, of which the following is a specification.

This invention relates to improvements in motion picture machines and particularly to improvements in the so-called ten sion guides for maintaining the film in poaperture.

in motion picture machines as new universally constructed the film is fed intermittently past the aperture to bring the successive pictures on the film strip into registration with the aperture for projection on the screen. As the motion of the film is ertremely rapid, the complete substitution of the successive pictures being effected in about one eightieth of a second, it is esserr tiahthat means be provided to bring the film to an immediate stop on the cessation of themovement of the intermittent sprocket and to maintain it fixed during the interval of projection, as otherwise the picture on the screen will be blurred by the movement or vibration of the film.

For this purpose it is customary to pro vide on each side of the aperture a springheld shoe pressing against the margin of the film to act as a brake applying. a fixed resistance to the passage of the film across the aperture when the film is in motion and holding the film taut at the aperture when the film is stationary. The springs for the tension shoes which are necessarily delicate, are subject to vibrations produced by the passage ofthe film acrossthe face of thetension shoes, and howevercarei'ully constructed, are subject to occasional breakage, which renders the machine inoperative until, the spring can be repaired.

One object of my present invention is to provide a construction for tensioning. the film at the aperture constructed in separate unit and detachably mounted on the motion picture machine so that in the event of breakage or other accident to any of1ts parts aced.

' Specification of Letters Patent.

moments time;

TENSION DEVICE FOR MOVING-PICTURE MACHINES.

Patented 'July 2, 1918.

- Application filed June 6,1916. swarm. 102,069.

by a duplicate device to thereby avoid in terruption of the exhibition for more than a A further object of the invention is to vide a construction of this character, especially adapted for machines in which the mechanism is inclosed in a complete casing for protectionagainst fire, in which the tension of the springs and consequently the. pressure on the film at the aperture may be easily and delicately adjustrl from without the casing without stopping the machine or interfering with the exhibition. of the picture.

A further object of the invention is to provide a tensioning device consisting of separate upper and lower 'members, each member having a separate spring and arranged so that the breakage of the spring for oneniember will not interfere with the operation of the other member, whereby the operation of the machine may be continued with the single member until'tlie end or" the reel or other convenient point for sto ping proto substitute the duplicat'e tension device, is

reached.

The invention also provides means whereby both springs are simultaneously anduniformly adjusted. by the single adjusting member outside of the casing.

In the accompanying drawings I have illustrated a preferred embodiment of my invention as shown the subject-matter of my copendirig-appli- 'progection aperture 2 is formed and across the face of which the film is guided. On

in connection with an improved moving picture. machine form ng each side of the aperture 2 a track or marginal guide 5 is provided for coiiperation ing against the projections with a detachable hinge pin be readily withdrawn to release the bridge with the tension shoes to hold the film in proper position in front of the aperture and. guide it in its passage from the upper to the lower feed devices. The tension devices matter of this application are supported on the inner face of the rear door or wall-3 of the casing in position for the film engaging shoes a to press against the film opposite the marginal guides 5 on each side of the aperture. The shoes 4: are arranged in upper and lower pairs, the shoes of each pair being connected by a cross piece 6 and each pair of shoes is supported in the carrying plate or bridge 7 by means of rearwardly bent projections 8 at the outer edge of each shoe, the projections extending through slots in the face of the plate. The shoes are held against displacement by means of plates 9 attached to each of theprojections back of the plate, the plates being arranged to permit the necessary movement of the shoes to secure the desired spring pressure against the film.

The bridge? is rearwardly bent side flanges 10 and 11, one of which is shaped to form a hinge for connecting the bridge to the door 3. The other flanges 11 are laterally bent to engage under forming the subj ecta rib 12 attached to the door 3 along the' other side of the aperture.

In order to permit the bridge to be readily disconnected from the door the hinge between the bridge and the bracket is provided 13 which may by means of its laterally bent upward end as shown in Fig. .1 of the drawing.

The spring pressure is applied to the shoes 4- by means of bow-springs 14, one of which is provided for each pair of shoes, the springs extending horizontally across the back of thebridge with their ends,press-' 8. The springs are supported on a plate 15 hinged to the edge of the bridge adjacent the supporting hinge, the hinged portions of the bridge being formed by oppositely bending the metal compressed by intermediate the parts of the first hin e in the opposite direction as The springs 14 are pivotally mounted above and below the edges of the plate 15 on 'vert1- cal pins 16 attached to the-backs of the springs at their middle points, and turning in suitable eyes formed in the edges of the plate 15.

The tension of the springs is adjusted by i means of an adjusting screw 17 threaded inthe door 3 pressing against the plate 15 to" thereby equally distributethe pressure of the two springs. The springs are suficiently the adjusting screw to hold the edge of the bridge agai t the rib 12 when the door is open and the springs may 7 tance permitted by the age of the spring of one formed at each edge with indicated in E g. 2.

After the film is brought across the aperture the door 3 is closed to bring the tension shoes into engagement with the margin of the film to hold the film in position for operation. The door is provided with a latch 18 for holding it closed.

In operation the tension shoes act in the usual manner to retard the intermittent movement of the film and hold the film at 4 rest during the projection of the picture.

The division of the tension shoes in two separate pairs distributes over the film and in the event of the breakpair of shoes the exhibition need not immediately be halted, but by increasing the pressure of the other spring through for the exhibition to be continued until the entire reel has been shown. The entire tension mechanism may then be removed as a unit by simply withdrawing the hinge pin with the emulsion which unavoidably spreads to some extent to the margins of the film, as

to ofier an undue'resista'nce to the movement of the film rendering it liable to be torn by the pull of the intermittiit. In such case the entire tension device may the exhibition than is necessary to clean the emulsion off of the shoes. 7

Another advantage of my improved. mechanism is the space provid bridge and the door which may be used-for a safety shutter, as in my copending appli cation before referred to. It is desirable to provide this space also for the purpose of allowing circulation bridge and the gate to prevent the bridge and its attached parts overheating. -The loose connection between the shoes and the bridge also prevents the shoes receiving much heat by conduction, which is desirable 1 to avoid as far as possible softening the emulsion on the film.

I claimi 1. A tension, devicefor moving picture machines comprising a gate hinged to the 1 machine frame, a supporting member detachably connected to said gate and tension devices for both marginal edges of the film wholly supported on said detachable mem her, said supportin member and tension. devices being detachable as a unit from said gate.

2. In a tension device for moving picture machines a supporting member detachably connected to the machine frame, a film enthe pressure evenly so the adjusting screw 17 the 85 film is sufficiently retarded by a single shoe beea'sily re- 10( placed with a much shorter'interruption of ed between the 10 of air between the 1] machines a supporting member detachablyconnected to the machine frame, a pair of film engaging members movably supported in said suiporting member and having shoes positions to engage the opposite margins of the film, a spring for each of said members pressing said shoes against the film and a member supporting both said springs ivotally mounted on said supporting mem er.

machines a supporting mg member,

4. In a tension device for moving picture member detachably connected to the machine frame, a film engaging member movably supported in said supporting member and having shoes positioned to engage the opposite margins of the film, a spring pressing said shoes against the film. and a member supporting said spring pivotally mounted onsaid supportan abutment for said spring carried b5 the frame wherebysaid spring holds sai supporting member against lost motion.

5. In a tension device for moving picture machines comprising a supporting member having a detachable pivotal connection with the'machine at one edge of said member, a stop attached to said machine. and engaging the opposite edge of saidmembena film engaging part movably mounted in said supporting member, a spring engaging said part for pressing sad part agamst the film and an abutment for said spring carried by the machine whereby said spring holds saidsupporting member against said stop.

In a moving picture machine having a fixed frame part provided with a pro ec-' tion aperture, a hinged gate mounted for movement toward and from said aperture, a tension device for the film carried by said gate, said tension device comprising a supporting member detachably mounted on said gate, film engaging parts for yieldingly engaging both margins of the film mount on said' su porting member, and a single connection etween said supporting member and said gate whereby said supporting member and tension devices are detachable as a unit.

7. In a moving picture machine having a fixed frame part provided with a projection aperture, a hinged gate mounted for movement toward and from said aperture, a tension device for the film at the aperture carried by said gate, said tensiondevice comprising a supporting member detachably mounted on said gate and 1a plurality of separate film engaging parts for yieldingly engaging both margins of the film mounted on said supporting member, separate springs for said parts positioned between said gate and said member, a common support for said s rings, said support being mounted on sai member, and means operatable'from the opposite gate for adjusting said springcarrying member to vary the tension of said springs.

Si ed at New York city, in the county of ew York and State of New York this 19th day of May, 1916.

NICHOLAS POWER.

at the aperture 

